Natto = fermented soybeans – a slimy and smelly Japanese food – just any old soybean won’t do; it has to be the fermented variety.

Vitamin K2 was my pet topic last year – much to my children’s disgust – they complained vociferously about the fetid natto that I had been force-feeding myself.

There’s no way of putting it nicely – natto emits an unpleasant smelly sock aroma.
And for my sins I used to down some natto every morning with a smidgen of turmeric in a cup of hot water. I did this for a few months at the beginning of 2014 – after the first couple of weeks I stopped gagging on it. I would go so far as to say that I almost got used to swallowing natto like a bitter pill. The other day I said to my youngest son that it would be a pity if I were to get run over by a bus – all these concoctions and bizarre regimes that I have been trying out on myself will have been to no avail if I die young, (or ‘youngish’ I should say).
He looked at me as if I were mad…

Last year I was a bit obsessed with vitamin K2 and I read just about everything that had ever been published on vitamin K2 – from Dr Weston A Price’s book ‘Nutrition and Physical Degeneration’ written in the 1930’s, down to all the latest research papers.

One of the things that I came across while trawling the internet was that a high intake of vitamin K2 is one of the things that the long lived French and Japanese have in common – the Japanese get it from natto, and the French get it from goose liver and fermented cheeses. This got me very interested in K2.

And what exactly is it that vitamin K2 does?
One of the key effects of K2 is that it channels calcium into the right places – into bones and out of arteries.

Currently vitamin K2 is the only known mechanism that the human body has for clearing calcium from arteries – how does it do this?
It activates various proteins, which in turn send calcium along the correct path.

So where should calcium not be going?
Into our arteries and blocking them – ‘calcium plaques’ are one of the hallmarks and risk factors for having a heart attack; these plaques are the blockages in your arteries that can predispose you to having a heart attack.

Studies on animals
Studies have shown that an adequate dietary intake of vitamin K2 reduces your chances of developing these calcium plaques; and experiments on animals have revealed that K2 might also reduce the size of pre-existing plaques. That’s pretty big as far as I’m concerned – it had me reaching for the natto in my local Japanese grocery store.

Studies on humans
Now for some evidence on humans – The Rotterdam Study in 2004 looked at the intake of vitamin K2 in 8000 men and women and found that individuals with the highest dietary K2 intake lived on average 7 years longer than K2 deficient people – a high intake of K2 apparently reduces the incidence of arterial calcification and risk of death from cardiovascular disease by 50% compared to people with a low dietary K2 intake.

Vitamin K2 and osteoporosis
The other big thing that convinced me to start with the natto was the benefits of vitamin K2 on osteoporosis.

According to the International Osteoporosis Foundation 1 in 2 women over the age of 50 in the UK will suffer a fracture at some point. As I am a woman over the age of 50 living in the UK this statistic doesn’t bode well for me. Time to do something about it.

A fair bit of the evidence on the benefits of vitamin K2 comes from the University of Maastricht in the Netherlands and from Japanese universities.

The Japanese have been looking into the link between K2 and osteoporosis for the last decade or so – they are well placed to look into it as they have some of the highest blood levels of K2 in the world due to their consumption of natto.

Possibly the Dutch have an interest in it because they eat a lot of Gouda which is purportedly high in K2?

A 3-year study on the effects of a low dose of vitamin K2 on 224 postmenopausal women in the Netherlands showed significant improvements in bone strength, a reduction in the age-related decline in bone mineral density and a reduction in loss of height compared to the control group.

And a study done last year in Japan showed similar results – low dose vitamin K2 supplementation in postmenopausal Japanese women for 12 months led to improved bone quality, without any substantial side effects.

Vitamin K2 and brains – start filling up on K2 to benefit your brain
As if the effects of vitamin K2 on heart attacks and osteoporosis weren’t enough, it seems to be crucial also for our brains and the entire nervous system as well.

Levels of K2 in the brain reflect dietary intake, and dietary intake of K2 seems to alter something called ‘brain sphingolipid metabolism’; and this in turn is linked to the ageing process, to Alzheimer’s disease and also to Parkinson’s disease.

Vitamin K2 and diabetes
There are a couple of studies, one from the Netherlands and the other from Korea, which show a link between vitamin K2 intake and diabetes – K2 seems to improve insulin sensitivity and reduce one’s risk of diabetes.

Vitamin K2 might also be involved in preventing tooth decay, cancer and dementia
A respected dentist and researcher by the name of Dr Weston A Price wrote a fascinating book in the 1930’s – after 40 years of practice he and his wife travelled the world in order to study populations who had no tooth decay, and he put all the findings into a seminal book.

The Prices went to 14 different countries to study healthy people in remote regions of the world with no access to modern foods – the Inuit; Native Americans; Outer Hebrides Islanders; remote Swiss Villages; African tribes, aborigines, Polynesia, Africa

Even though all these people in different parts of the world had remarkably diverse diets, Dr Price discovered that they all had no tooth decay (despite no toothbrushes or toothpaste!) and also appeared to be immune to most Western diseases as well as to tuberculosis. He made the link between dental health and cardiovascular disease nearly a century ago – a man well before his time.

Dr Price also found that these peoples had no orthodontic problems, yet when they moved to urbanised areas their children were born with narrow dental arches. Amazingly if they had several children only the ones born while the mother had a traditional diet had normal arches – successive children born after adopting a Western diet had narrow arches, overcrowded mouths and in dire need of orthodontic treatment.

All of this evidence was meticulously documented, with very precise figures as well photographs to back up and confirm his extraordinary findings.

He put down some of the health discrepancies between Westerners and traditional people to a substance that he called ‘Activator X’, which was present in organ meats and in butter from grass fed cows. This ‘Activator X’ has subsequently been shown to be vitamin K2.

He found that feeding ‘Activator X’ to children with rampant dental decay prevented further decay, and in some cases even reversed pre-existing decay.

Besides the lack of ‘Activator X’ in Western diets, the other differences were the presence of large amounts of sugar, alcohol, white flour and processed oils in urban diets.

As we’re on the topic of vitamin K2, I should mention vitamin K1 as well
Vitamin K1 is old hat – its role in the body is well established; it is crucial for normal blood clotting, and a deficiency of K1 can cause you to bleed to death, so a lack of vitamin K1 isn’t really compatible with life.

With vitamin K1 deficiency a quick death from a haemorrhage might ensue; unlike a lack of K2 which seems to cause a long and slow degeneration, ultimately leading to death.

The main reason why vitamin K1 deficiency is rare is because it is present in green vegetables, which are easily available in most diets.

Vitamin K2 deficiency

Consumption of vitamin K2 seems to have fallen drastically worldwide in the last 50 years; according to some researchers we may be in the middle of a global epidemic of K2 deficiency.

Current understanding of K2 is limited – it is an exciting new field of research – there is growing recognition of the worldwide deficiency and an awareness of the health benefits of K2.

Vitamin K2 is the new kid on the block in the vitamin world.

All this is reminiscent of when vitamin D hit the headlines about 10 years ago.

The other important thing to know about vitamin K2 is that it works together with vitamin D.

Vitamin D helps you absorb calcium, and after calcium is absorbed, vitamin K2 directs it into the right places.

So if you have high calcium levels, but low vitamin K2 levels, calcium might end up in places where it oughtn’t to be – e.g. in arteries as mentioned already.

Most importantly, if you have inadequate levels of K2 and at the same time take vitamin D and calcium supplements, you might be setting yourself up for problems in the future (the vitamin D increases calcium absorption, and the calcium accumulates as ‘plaques’ in your arteries because of insufficient K2 to clear it away).

How do animals get vitamins K1 and K2? And is this relevant to humans?
Animals are good at converting vitamin K1 to K2, but humans aren’t, so we need to obtain K2 from our diets, whereas animals don’t.

As green vegetables are a good source of vitamin K1, animals need to eat ‘greens’ such as grass to have adequate levels of K1, which they can then convert to K2.

If animals are fed grains instead of green grass they have lower levels of K1 and hence lower levels of K2 as well, (because grains unlike grass are low in vitamin K1).

And if humans eat dairy and animal products from grain fed animals, we will therefore be consuming lower levels of K2 than we would from grass fed animals.

We aren’t just ‘what we eat’; we are also what our animals eat
So why don’t we all just take vitamin K2 supplements and have done with it?

That’s a personal choice – I’m wary of taking supplements because time and again studies over the years have shown that obtaining a nutrient from food is usually better and safer than obtaining it from a supplement.

The exception to this rule being vitamin D – it is almost impossible to get all the vitamin D that you need from your diet – unless you live on fish like the Inuit, live at a high altitude like the Swiss, or you are in the sun for between 10 and 60 minutes a day (depending on your skin colour), so that your skin can synthesise vitamin D.

And if you live far from the tropics the sun isn’t strong enough in winter for you to make vitamin D.

Back to the K vitamins – it should now come as no surprise that the VKD (vitamin K-dependent proteins) are now known to be present in virtually every tissue in the body; according to the Department of Molecular Cardiology in Cleveland, these ‘VKD’ are thought to be important not only in bone mineralization and arterial calcification, but also in many other important processes in the body.